package test;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.locks.ReentrantLock;

/**
 * @Description
 * @Date 2021/10/22
 * @Created by Jonathan
 */
public class Main {
    public static void main(String[] args) {
        Map<String, Object> map = new HashMap<>();
        //ArrayList
        map.put("1", "1");
        ReentrantLock lock = new ReentrantLock(true);
        lock.lock();
        lock.unlock();
        new ConcurrentHashMap<>();
        Timer timer = new Timer();
        timer.scheduleAtFixedRate(new TimerTask() {
            @Override
            public void run() {
                System.out.println("hello world");
            }
        },0,1000);
    }
}
